In recent years, the use of computer networks for communication and data processing has become increasingly widespread. The increased availability and use of computer networks has created possibilities for new kinds of business and interactions. For example, many people now conduct business transactions, such as banking or retail transactions, over the Internet or private computer networks. Others use the Internet to participate in interactive, multi-party games that could not have existed before the advent of computer networks.
Computer network users generally attempt to exploit the unique features inherent in communications over computer networks. Owners of valuable data or "content," such as software developers or entertainment companies, take advantage of the relative ease and speed of data replication and transmission over computer networks to inexpensively distribute their data to vast audiences. Retailers and advertisers utilize the relative cost-effectiveness and ready searchability (as compared to conventional publishing media) of data published on the World Wide Web to make information available to vast bodies of potential customers. Multinational businesses use the medium to allow immediate and inexpensive communication among employees in various parts of the world.
In each of the above situations, technical challenges must be overcome. Content providers generally seek mechanisms to ensure receipt of payment for any copies of their content which are distributed, and to ensure the integrity of the data transmission. Retailers desire mechanisms for conducting secure commercial transactions over the Internet. Those communicating at a distance often require security and confidentiality of data transmission, and means of authenticating the origin of data received.
These challenges generally are overcome by applying common cryptographic techniques to eliminate data security or privacy concerns, while still allowing users to take advantage of the unique features of the new medium. For example, common cryptographic techniques are available to allow authentication of the sender of a digital message, and to ensure that such a message is opened only by the intended recipient. Data metering systems provide a mechanism for content providers to charge for use of their data. A software provider may also use a conventional "digital signature" to sign code that is being distributed to users, thereby allowing users to rely on the quality of the code received.
In some cases, however, it is desirable to eliminate certain perceived "advantages" or inherent features of the new medium, and extend familiar limitations of the physical world into the electronic realm. In the case of digital cash, for example, it is necessary to prohibit "counterfeiting." This is accomplished by introducing digital equivalents of the security features that protect against counterfeit paper currency.
Traditional features and limitations of ownership and property rights are also sometimes desirable within the computer network environment. In an interactive game environment, for example, users might purchase or otherwise obtain "property" which can be voluntarily or involuntarily transferred to other users. This game "property" may represent a physical item that, in the context of the game, should not be counterfeited or duplicated readily. Thus, for example, the seller of a game object should not be able to retain a usable copy of the sold item.
Previously, there was no adequate, reliable and sufficiently secure system for establishing traditional features of ownership and property rights in the digital realm. Accordingly, there is a need for an improved system of property ownership and transfer that can be implemented in connection with a computer network.